Providing an improved web user interface framework for building web applications

ABSTRACT

Disclosed are methods, systems, and computer program products for updating a web application displayed on a client machine. In some implementations, a server maintains a database of application identifiers identifying instances of one or more web applications. The server receives, from a first client machine, a communication identifying a first web application and a first application identifier, the instance of the first web application being associated with one or more components. The server determines that the first application identifier is not included in the database of application identifiers, and generates an updated application identifier for the instance of the first web application based on component version identifiers of the one or more components. The server stores the updated application identifier and transmits a notification to the first client machine indicating that the instance of the first web application is out-of-date.

PRIORITY DATA

This patent document claims priority to commonly assigned U.S.Provisional Patent Application No. 61/862,690, titled “Aura UniversalIDs,” by Oliver et al., filed on Aug. 6, 2013, which is herebyincorporated by reference in its entirety and for all purposes.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains material,which is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

TECHNICAL FIELD

This patent document relates generally to on-demand services providedover a data network such as the Internet, and more specifically toproviding an improved web user interface framework for building webapplications.

BACKGROUND

Organizations typically employ many different types of software andcomputing technologies to meet their computing needs. However,installing and maintaining software on an organization's own computersystems may involve one or more drawbacks. For example, when softwaremust be installed on computer systems within the organization, theinstallation process often requires significant time commitments, sinceorganization personnel may need to separately access each computer. Onceinstalled, the maintenance of such software typically requiressignificant additional resources. Each installation of the software mayneed to be separately monitored, upgraded, and/or maintained. Further,organization personnel may need to protect each installed piece ofsoftware against viruses and other malevolent code. Given thedifficulties in updating and maintaining software installed on manydifferent computer systems, it is common for software to becomeoutdated. Also, the organization will likely need to ensure that thevarious software programs installed on each computer system arecompatible. Compatibility problems are compounded by frequent upgrading,which may result in different versions of the same software being usedat different computer systems in the same organization.

Accordingly, organizations increasingly prefer to use on-demand servicesaccessible via the Internet rather than software installed on in-housecomputer systems. On-demand services, often termed “cloud computing”services, take advantage of increased network speeds and decreasednetwork latency to provide shared resources, software, and informationto computers and other devices upon request. Cloud computing typicallyinvolves over-the-Internet provision of dynamically scalable and oftenvirtualized resources. Technological details can be abstracted from theusers, who no longer have need for expertise in, or control over, thetechnology infrastructure “in the cloud” that supports them.

BRIEF DESCRIPTION OF THE DRAWINGS

The included drawings are for illustrative purposes and serve only toprovide examples of possible structures and operations for the disclosedinventive systems, apparatus, methods, and computer program products.These drawings in no way limit any changes in form and detail that maybe made by one skilled in the art without departing from the spirit andscope of the disclosed implementations.

FIG. 1A shows a block diagram of an example of an environment 10 inwhich an on-demand database service can be used in accordance with someimplementations.

FIG. 1B shows a block diagram of an example of some implementations ofelements of FIG. 1A and various possible interconnections between theseelements.

FIG. 2A shows a system diagram illustrating an example of architecturalcomponents of an on-demand database service environment 200 according tosome implementations.

FIG. 2B shows a system diagram further illustrating an example ofarchitectural components of an on-demand database service environmentaccording to some implementations.

FIG. 3 shows a flowchart of an example of a computer implemented method300 for updating a web application displayed on a client machine,according to some implementations.

FIG. 4 shows a flowchart of an example of a computer implemented method460 for refreshing a web application, according to some implementations.

FIG. 5 shows an example of a graphical user interface (GUI) 500 for aweb application containing one or more components, according to someimplementations.

FIG. 6 shows a flowchart of an example of a computer implemented method600 for storing client-side information for identifying and requestingserver-side actions, according to some implementations.

FIG. 7 shows a flowchart of an example of a computer implemented method750 for a mobile device causing the first and second requests to becommunicated to the server, according to some implementations.

FIG. 8 shows a flowchart of an example of a computer implemented method800 for displaying in a web browser a presentation of a server-hostedweb application with an embedded component, according to someimplementations.

FIGS. 9A and 9B show flowcharts of examples of computer implementedmethods 930 and 940 for responding to an event raised by a component ofthe web application, according to some implementations.

FIG. 10 shows an example of a GUI 1000 for an instance of a webapplication containing one or more components, according to someimplementations.

DETAILED DESCRIPTION

Examples of systems, apparatus, methods, and computer program productsaccording to the disclosed implementations are described in thissection. These examples are being provided solely to add context and aidin the understanding of the disclosed implementations. It will thus beapparent to one skilled in the art that implementations may be practicedwithout some or all of these specific details. In other instances,certain process/method operations, also referred to herein as “blocks,”have not been described in detail in order to avoid unnecessarilyobscuring implementations. Other applications are possible, such thatthe following examples should not be taken as definitive or limitingeither in scope or setting.

In the following detailed description, references are made to theaccompanying drawings, which form a part of the description and in whichare shown, by way of illustration, specific implementations. Althoughthese implementations are described in sufficient detail to enable oneskilled in the art to practice the disclosed implementations, it isunderstood that these examples are not limiting, such that otherimplementations may be used and changes may be made without departingfrom their spirit and scope. For example, the blocks of methods shownand described herein are not necessarily performed in the orderindicated. It should also be understood that the methods may includemore or fewer blocks than are indicated. In some implementations, blocksdescribed herein as separate blocks may be combined. Conversely, whatmay be described herein as a single block may be implemented in multipleblocks.

Various implementations described or referenced herein are directed todifferent methods, apparatus, systems, and computer program products forproviding an improved web user interface framework for building webapplications.

Web application frameworks, or user interface (UI) frameworks, enableweb developers to develop dynamic websites, web applications, and webservices to run on a variety of platforms. UI frameworks are used inpart to alleviate the overhead associated with common activitiesperformed in web development. They may provide libraries for databaseaccess, templating frameworks, and session management, and they may alsoprovide methods of code reuse for more efficient web applicationdevelopment.

Increasingly, UI frameworks are being used to develop dynamic webapplications that are accessible from mobile devices. One key aspect ofbuilding web applications to be accessed from mobile devices isaccounting for the bandwidth constraints that many mobile device usersface. As such, it is desirable for a UI framework to minimize the amountof data and communication that needs to happen between the serverhosting the web application and the client rendering the user interfaceof the web application. Some ways in which this can be done is byrefreshing components displayed in the user interface only whennecessary, that is, when a component's definition has been updated onthe server. Moreover, caching component definitions locally, such thatcomponent definitions do not have to be requested from the server everytime the user interface is refreshed, may also minimize the bandwidthusage of the web application.

A desirable feature of a UI framework is having a rich set of componentsthat are reusable and extensible. A component may be any self-containedand reusable unit of a UI presenting a web application, such as abutton, a text field, or a list, and a component may be used in any webapplication UI that includes the component. A component has a clearApplication Programming Interface (API) that instructs a developer thatwants to include the component in his application how to use thecomponent. Having a clear API allows the internal implementation detailsof the component to be opaque to a user of the component. It also allowsa component author to change the internal implementation details of thecomponent without affecting the users of the component. A component mayalso have a component version identifier indicating the current versionof the component.

In some of the disclosed implementations, a client machine may bedisplaying in a web browser an instance of a server-hosted webapplication that includes a set of components. Once the componentdefinitions have been transmitted to the client machine, the clientmachine may locally cache the component definitions and use those cacheddefinitions for the components to render the components in the userinterface on the client machine. In the meantime, the component authormay have pushed out an update of one of the components. Because theclient machine is using a locally cached component definition, it isdesirable to have a mechanism for detecting when an instance of a webapplication contains an out-of-date component and informing the clientmachine displaying that the user interface of that instance of the webapplication, while keeping the web application running smoothly.

Some of the disclosed implementations compute an application identifierfor an instance of a web application. The application identifier isbased on the component version identifiers for all of the componentsbeing used in the user interface for the instance of the webapplication. When a component is updated, the component versionidentifier for that component changes. When the component versionidentifier of a component changes, the calculation that generates theapplication identifier for the instance of the application containingthe component will produce an updated application identifier that isdifferent from the application identifier previously generated for theinstance of the web application containing the previous component. Bymaintaining a server-side index of application identifiers for instancesof web applications being displayed at various client machines, theserver, upon being notified of an updated component, may determine whichweb application instances need to be updated.

A client machine displaying a user interface for a web applicationinstance may identify the application identifier representing theversion of the web application being displayed each time the clientmachine sends a request up to the application server. When theapplication is initially requested by the client machine, the server maycompute and store an application identifier for the application in adatabase. However, when a component is updated, the server may gothrough the database and remove all application identifiers for webapplication instances containing the updated component. The next timethat the client machine sends the server a request containing itsapplication identifier, the server will be unable to find theapplication identifier in the database, which notifies the server thatat least one component of the web application instance displayed on theclient machine has been updated. The server may then inform the clientmachine accordingly. The client machine may then request a refresh ofthe user interface of the web application with the updated components.Thus, the disclosed implementations provide users of web applications toseamlessly view and interact with components that are concurrently beingupdated by component developers.

Another desirable feature for a UI framework is a mechanism for locallycaching responses to server-side actions on the client. A client webapplication may benefit from caching data to reduce webpage responsetimes by storing and accessing data locally rather than requesting datafrom the server. This may enhance the user experience on the client. Inparticular, caching is beneficial for high-performance, mostly-connectedapplications operating over high latency connections, such as 3Gnetworks. Caching may also benefit applications running on devices thattemporarily do not have a network connection by providing a mechanismfor gracefully falling back on cached information when there is noserver connectivity. Moreover, using radio networks on a mobile deviceis relatively costly, so minimizing radio network usage while operatinga web application could be advantageous in terms of both cost andefficiency.

In some of the disclosed implementations, the web application maytransmit a request to the server to perform a server-side action. Foractions that are frequently performed by the server, it may beadvantageous to cache, on the client, the responses to frequentlyperformed actions so that they may be quickly retrieved at a later timewithout performing another server request. These actions may beidentified by the UI framework as “storable actions.” The action resultsmay be stored in the cached and the results may be indexed by theaction. In that way, when a component requests that a storable action beperformed by the server, the web application may first check the cacheto see if there is a response that can be supplied to the componentwithout submitting a new request to the server.

The manner in which requests from various components of a webapplication to execute storable actions are sent to the server and themanner in which responses are received from the server may be managed byan API that facilitates communication between the client and server at alayer of abstraction above the individual XML HTTP requests from variouscomponents of an application. The API allows the web application tomanage the multiple simultaneous connections between the components ofthe application and the server. Requests from the various components maybe coordinated, bundled, and transmitted to the server in a singlerequest to be executed on the server. The results of the executedstorable actions may be bundled and transmitted back to the webapplication in a single response as well.

On the client end, a local caching policy may determine how storableaction results received from the server are cached and/or provided tothe components requesting the storable actions. The local caching policymay dictate what type of storage to use when caching the results of astorable action. The storage type may be persistent and/or durable.Depending on the user's selection of what storage type to use, variousstorage adapters may be provided by the UI framework to interact withthe cache. For example, the metadata involved in determining how accountinformation should be displayed in an application may be rather large,relative to the actual account information being displayed, and it maybe desirable to keep the account display metadata cached locally so thatit does not need to be retransmitted from the server every time anaccount is displayed. It would be desirable for the storage used for theaccount display metadata to be persistent, so that the browser does notdelete the metadata between browser sessions, requiring another requestfor the metadata.

The local caching policy may also include policies on how cachedresponses are provided to components requesting a storable action. Thepolicies may be implemented on a per-action level or on global level.For example, the local caching policy may dictate that for a particularstorable action, the web application should provide the cached responseto the component requesting the storable action, as long as the cachedresponse has not exceeded the expiration time of sixty minutes. Asanother example, the local caching policy may dictate that the webapplication provide the component with the cached response, whileconcurrently sending a request to the server for an updated response tothe storable action. The component is first given the cached response,and when the updated response is subsequently returned by the server,the web application may provide the updated response to the componentand update the cache with the updated response.

In other implementations, the response from the server may include theresults of actions that were not requested by the web application. Theseresults are “pre-fetched” results for storable actions that arepredicted as likely to be requested by a component of the webapplication. The prediction may be performed using a set of heuristicsthat connect certain storable actions with other storable actions thatare likely to be requested after the former storable actions arerequested. For example, a user may send a request to the server tosearch for a particular opportunity based on a keyword. The server mayidentify a list of opportunities that match the keyword. The server mayalso predict that the user will select one or more of the opportunitiesin the list, and the server may pre-fetch the opportunities results byperforming the appropriate server-side actions and send the pre-fetchedresults along with the opportunity list in the response to the server.Thus, when the user, when presented with the list of opportunities,selects the first opportunity, the web application may immediately serveup the opportunity information from the local cache, rather than sendinganother request to the server.

One other desirable feature of a UI framework is to be able to take thecomponents that are developed within the UI framework and embed them inother web technologies. For example, there may be some componentsdeveloped in the UI framework that have wide application outside of webapplications built on the UI framework. In the disclosedimplementations, these self-contained and reusable components may alsobe embedded in web applications hosted on other application servers,while the embedded components themselves may be hosted from the serverson which the components were developed. In this way, any web applicationusing nearly any given web technology may take advantage of thecomponents that are built and developed on the UI framework. Thedisclosed implementations provide a set of APIs to allow a user to embedsuch a component in a web application.

For example, the Dell Company employee intranet may include some objectsin its content management system (CMS) that are also backed by aSalesforce database and are associated with a Salesforce record ID. Anadministrator of the Dell intranet may want to provide Dell employeesnavigating the intranet with a Chatter® feed component for viewingrecent updates to objects in the CMS that are backed by the Salesforcedatabase. The Chatter® feed is a component that is developed and hostedon the Salesforce servers, and the Dell administrator, using thedisclosed implementations, may embed a context-sensitive Chatter® feedin the Dell intranet web application. As the user browses variousobjects in the Dell intranet, the Chatter® feed may automatically updateto include updates pertaining to the objects that the user is browsingin the intranet.

These and other implementations may be embodied in various types ofhardware, software, firmware, and combinations thereof. For example,some techniques disclosed herein may be implemented, at least in part,by computer-readable media that include program instructions, stateinformation, etc., for performing various services and operationsdescribed herein. Examples of program instructions include both machinecode, such as produced by a compiler, and files containing higher-levelcode that may be executed by a computing device such as a server orother data processing apparatus using an interpreter. Examples ofcomputer-readable media include, but are not limited to, magnetic mediasuch as hard disks, floppy disks, and magnetic tape; optical media suchas CD-ROM disks; magneto-optical media; and hardware devices that arespecially configured to store program instructions, such as read-onlymemory (“ROM”) devices and random access memory (“RAM”) devices. Theseand other features of the disclosed implementations will be described inmore detail below with reference to the associated drawings.

I. General Overview

Systems, apparatus, methods, and computer program products are providedfor implementing enterprise level social and business informationnetworking. Such implementations can provide more efficient use of adatabase system. For instance, a user of a database system may noteasily know when important information in the database has changed,e.g., about a project or client. Implementations can provide feedtracked updates about such changes and other events, thereby keepingusers informed.

By way of example, a user can update a record, e.g., an opportunity suchas a possible sale of 1000 computers. Once the record update has beenmade, a feed tracked update about the record update can thenautomatically be provided, e.g., in a feed, to anyone subscribing to theopportunity or to the user. Thus, the user does not need to contact amanager regarding the change in the opportunity, since the feed trackedupdate about the update is sent via a feed right to the manager's feedpage or other page.

Next, mechanisms and methods for providing systems implementingenterprise level social and business information networking will bedescribed with reference to several implementations. First, an overviewof an example of a database system is described, and then examples oftracking events for a record, actions of a user, and messages about auser or record are described. Various implementations about the datastructure of feeds, customizing feeds, user selection of records andusers to follow, generating feeds, and displaying feeds are alsodescribed.

II. System Overview

FIG. 1A shows a block diagram of an example of an environment 10 inwhich an on-demand database service can be used in accordance with someimplementations. Environment 10 may include user systems 12, network 14,database system 16, processor system 17, application platform 18,network interface 20, tenant data storage 22, system data storage 24,program code 26, and process space 28. In other implementations,environment 10 may not have all of these components and/or may haveother components instead of, or in addition to, those listed above.

Environment 10 is an environment in which an on-demand database serviceexists. User system 12 may be implemented as any computing device(s) orother data processing apparatus such as a machine or system that is usedby a user to access a database system 16. For example, any of usersystems 12 can be a handheld computing device, a mobile phone, a laptopcomputer, a work station, and/or a network of such computing devices. Asillustrated in FIG. 1A (and in more detail in FIG. 1B) user systems 12might interact via a network 14 with an on-demand database service,which is implemented in the example of FIG. 1A as database system 16.

An on-demand database service, implemented using system 16 by way ofexample, is a service that is made available to outside users, who donot need to necessarily be concerned with building and/or maintainingthe database system. Instead, the database system may be available fortheir use when the users need the database system, i.e., on the demandof the users. Some on-demand database services may store informationfrom one or more tenants into tables of a common database image to forma multi-tenant database system (MTS). A database image may include oneor more database objects. A relational database management system(RDBMS) or the equivalent may execute storage and retrieval ofinformation against the database object(s). Application platform 18 maybe a framework that allows the applications of system 16 to run, such asthe hardware and/or software, e.g., the operating system. In someimplementations, application platform 18 enables creation, managing andexecuting one or more applications developed by the provider of theon-demand database service, users accessing the on-demand databaseservice via user systems 12, or third party application developersaccessing the on-demand database service via user systems 12.

The users of user systems 12 may differ in their respective capacities,and the capacity of a particular user system 12 might be entirelydetermined by permissions (permission levels) for the current user. Forexample, where a salesperson is using a particular user system 12 tointeract with system 16, that user system has the capacities allotted tothat salesperson. However, while an administrator is using that usersystem to interact with system 16, that user system has the capacitiesallotted to that administrator. In systems with a hierarchical rolemodel, users at one permission level may have access to applications,data, and database information accessible by a lower permission leveluser, but may not have access to certain applications, databaseinformation, and data accessible by a user at a higher permission level.Thus, different users will have different capabilities with regard toaccessing and modifying application and database information, dependingon a user's security or permission level, also called authorization.

Network 14 is any network or combination of networks of devices thatcommunicate with one another. For example, network 14 can be any one orany combination of a LAN (local area network), WAN (wide area network),telephone network, wireless network, point-to-point network, starnetwork, token ring network, hub network, or other appropriateconfiguration. Network 14 can include a TCP/IP (Transfer ControlProtocol and Internet Protocol) network, such as the global internetworkof networks often referred to as the “Internet” with a capital “I.” TheInternet will be used in many of the examples herein. However, it shouldbe understood that the networks that the present implementations mightuse are not so limited, although TCP/IP is a frequently implementedprotocol.

User systems 12 might communicate with system 16 using TCP/IP and, at ahigher network level, use other common Internet protocols tocommunicate, such as HTTP, FTP, AFS, WAP, etc. In an example where HTTPis used, user system 12 might include an HTTP client commonly referredto as a “browser” for sending and receiving HTTP signals to and from anHTTP server at system 16. Such an HTTP server might be implemented asthe sole network interface 20 between system 16 and network 14, butother techniques might be used as well or instead. In someimplementations, the network interface 20 between system 16 and network14 includes load sharing functionality, such as round-robin HTTP requestdistributors to balance loads and distribute incoming HTTP requestsevenly over a plurality of servers. At least for users accessing system16, each of the plurality of servers has access to the MTS' data;however, other alternative configurations may be used instead.

In one implementation, system 16, shown in FIG. 1A, implements aweb-based customer relationship management (CRM) system. For example, inone implementation, system 16 includes application servers configured toimplement and execute CRM software applications as well as providerelated data, code, forms, web pages and other information to and fromuser systems 12 and to store to, and retrieve from, a database systemrelated data, objects, and Webpage content. With a multi-tenant system,data for multiple tenants may be stored in the same physical databaseobject in tenant data storage 22, however, tenant data typically isarranged in the storage medium(s) of tenant data storage 22 so that dataof one tenant is kept logically separate from that of other tenants sothat one tenant does not have access to another tenant's data, unlesssuch data is expressly shared. In certain implementations, system 16implements applications other than, or in addition to, a CRMapplication. For example, system 16 may provide tenant access tomultiple hosted (standard and custom) applications, including a CRMapplication. User (or third party developer) applications, which may ormay not include CRM, may be supported by the application platform 18,which manages creation, storage of the applications into one or moredatabase objects and executing of the applications in a virtual machinein the process space of the system 16.

One arrangement for elements of system 16 is shown in FIGS. 1A and 1B,including a network interface 20, application platform 18, tenant datastorage 22 for tenant data 23, system data storage 24 for system data 25accessible to system 16 and possibly multiple tenants, program code 26for implementing various functions of system 16, and a process space 28for executing MTS system processes and tenant-specific processes, suchas running applications as part of an application hosting service.Additional processes that may execute on system 16 include databaseindexing processes.

Several elements in the system shown in FIG. 1A include conventional,well-known elements that are explained only briefly here. For example,each user system 12 could include a desktop personal computer,workstation, laptop, PDA, cell phone, or any wireless access protocol(WAP) enabled device or any other computing device capable ofinterfacing directly or indirectly to the Internet or other networkconnection. The term “computing device” is also referred to hereinsimply as a “computer”. User system 12 typically runs an HTTP client,e.g., a browsing program, such as Microsoft's Internet Explorer browser,Netscape's Navigator browser, Opera's browser, or a WAP-enabled browserin the case of a cell phone, PDA or other wireless device, or the like,allowing a user (e.g., subscriber of the multi-tenant database system)of user system 12 to access, process and view information, pages andapplications available to it from system 16 over network 14. Each usersystem 12 also typically includes one or more user input devices, suchas a keyboard, a mouse, trackball, touch pad, touch screen, pen or thelike, for interacting with a graphical user interface (GUI) provided bythe browser on a display (e.g., a monitor screen, LCD display, etc.) ofthe computing device in conjunction with pages, forms, applications andother information provided by system 16 or other systems or servers. Forexample, the user interface device can be used to access data andapplications hosted by system 16, and to perform searches on storeddata, and otherwise allow a user to interact with various GUI pages thatmay be presented to a user. As discussed above, implementations aresuitable for use with the Internet, although other networks can be usedinstead of or in addition to the Internet, such as an intranet, anextranet, a virtual private network (VPN), a non-TCP/IP based network,any LAN or WAN or the like.

According to one implementation, each user system 12 and all of itscomponents are operator configurable using applications, such as abrowser, including computer code run using a central processing unitsuch as an Intel Pentium® processor or the like. Similarly, system 16(and additional instances of an MTS, where more than one is present) andall of its components might be operator configurable usingapplication(s) including computer code to run using processor system 17,which may be implemented to include a central processing unit, which mayinclude an Intel Pentium® processor or the like, and/or multipleprocessor units. Non-transitory computer-readable media can haveinstructions stored thereon/in, that can be executed by or used toprogram a computing device to perform any of the methods of theimplementations described herein. Computer program code 26 implementinginstructions for operating and configuring system 16 to intercommunicateand to process web pages, applications and other data and media contentas described herein is preferably downloadable and stored on a harddisk, but the entire program code, or portions thereof, may also bestored in any other volatile or non-volatile memory medium or device asis well known, such as a ROM or RAM, or provided on any media capable ofstoring program code, such as any type of rotating media includingfloppy disks, optical discs, digital versatile disk (DVD), compact disk(CD), microdrive, and magneto-optical disks, and magnetic or opticalcards, nanosystems (including molecular memory ICs), or any other typeof computer-readable medium or device suitable for storing instructionsand/or data. Additionally, the entire program code, or portions thereof,may be transmitted and downloaded from a software source over atransmission medium, e.g., over the Internet, or from another server, asis well known, or transmitted over any other conventional networkconnection as is well known (e.g., extranet, VPN, LAN, etc.) using anycommunication medium and protocols (e.g., TCP/IP, HTTP, HTTPS, Ethernet,etc.) as are well known. It will also be appreciated that computer codefor the disclosed implementations can be realized in any programminglanguage that can be executed on a client system and/or server or serversystem such as, for example, C, C++, HTML, any other markup language,Java™, JavaScript, ActiveX, any other scripting language, such asVBScript, and many other programming languages as are well known may beused. (Java™ is a trademark of Sun Microsystems, Inc.).

According to some implementations, each system 16 is configured toprovide web pages, forms, applications, data and media content to user(client) systems 12 to support the access by user systems 12 as tenantsof system 16. As such, system 16 provides security mechanisms to keepeach tenant's data separate unless the data is shared. If more than oneMTS is used, they may be located in close proximity to one another(e.g., in a server farm located in a single building or campus), or theymay be distributed at locations remote from one another (e.g., one ormore servers located in city A and one or more servers located in cityB). As used herein, each MTS could include one or more logically and/orphysically connected servers distributed locally or across one or moregeographic locations. Additionally, the term “server” is meant to referto a computing device or system, including processing hardware andprocess space(s), an associated storage medium such as a memory deviceor database, and, in some instances, a database application (e.g.,OODBMS or RDBMS) as is well known in the art. It should also beunderstood that “server system” and “server” are often usedinterchangeably herein. Similarly, the database objects described hereincan be implemented as single databases, a distributed database, acollection of distributed databases, a database with redundant online oroffline backups or other redundancies, etc., and might include adistributed database or storage network and associated processingintelligence.

FIG. 1B shows a block diagram of an example of some implementations ofelements of FIG. 1A and various possible interconnections between theseelements. That is, FIG. 1B also illustrates environment 10. However, inFIG. 1B elements of system 16 and various interconnections in someimplementations are further illustrated. FIG. 1B shows that user system12 may include processor system 12A, memory system 12B, input system12C, and output system 12D. FIG. 1B shows network 14 and system 16. FIG.1B also shows that system 16 may include tenant data storage 22, tenantdata 23, system data storage 24, system data 25, User Interface (UI) 30,Application Program Interface (API) 32, PL/SOQL 34, save routines 36,application setup mechanism 38, applications servers 1001-100N, systemprocess space 102, tenant process spaces 104, tenant management processspace 110, tenant storage space 112, user storage 114, and applicationmetadata 116. In other implementations, environment 10 may not have thesame elements as those listed above and/or may have other elementsinstead of, or in addition to, those listed above.

User system 12, network 14, system 16, tenant data storage 22, andsystem data storage 24 were discussed above in FIG. 1A. Regarding usersystem 12, processor system 12A may be any combination of one or moreprocessors. Memory system 12B may be any combination of one or morememory devices, short term, and/or long term memory. Input system 12Cmay be any combination of input devices, such as one or more keyboards,mice, trackballs, scanners, cameras, and/or interfaces to networks.Output system 12D may be any combination of output devices, such as oneor more monitors, printers, and/or interfaces to networks. As shown byFIG. 1B, system 16 may include a network interface 20 (of FIG. 1A)implemented as a set of HTTP application servers 100, an applicationplatform 18, tenant data storage 22, and system data storage 24. Alsoshown is system process space 102, including individual tenant processspaces 104 and a tenant management process space 110. Each applicationserver 100 may be configured to communicate with tenant data storage 22and the tenant data 23 therein, and system data storage 24 and thesystem data 25 therein to serve requests of user systems 12. The tenantdata 23 might be divided into individual tenant storage spaces 112,which can be either a physical arrangement and/or a logical arrangementof data. Within each tenant storage space 112, user storage 114 andapplication metadata 116 might be similarly allocated for each user. Forexample, a copy of a user's most recently used (MRU) items might bestored to user storage 114. Similarly, a copy of MRU items for an entireorganization that is a tenant might be stored to tenant storage space112. A UI 30 provides a user interface and an API 32 provides anapplication programmer interface to system 16 resident processes tousers and/or developers at user systems 12. The tenant data and thesystem data may be stored in various databases, such as one or moreOracle| databases.

Application platform 18 includes an application setup mechanism 38 thatsupports application developers' creation and management ofapplications, which may be saved as metadata into tenant data storage 22by save routines 36 for execution by subscribers as one or more tenantprocess spaces 104 managed by tenant management process 110 for example.Invocations to such applications may be coded using PL/SOQL 34 thatprovides a programming language style interface extension to API 32. Adetailed description of some PL/SOQL language implementations isdiscussed in commonly assigned U.S. Pat. No. 7,730,478, titled METHODAND SYSTEM FOR ALLOWING ACCESS TO DEVELOPED APPLICATIONS VIA AMULTI-TENANT ON-DEMAND DATABASE SERVICE, by Craig Weissman, issued onJun. 1, 2010, and hereby incorporated by reference in its entirety andfor all purposes. Invocations to applications may be detected by one ormore system processes, which manage retrieving application metadata 116for the subscriber making the invocation and executing the metadata asan application in a virtual machine.

Each application server 100 may be communicably coupled to databasesystems, e.g., having access to system data 25 and tenant data 23, via adifferent network connection. For example, one application server 1001might be coupled via the network 14 (e.g., the Internet), anotherapplication server 100N−1 might be coupled via a direct network link,and another application server 100N might be coupled by yet a differentnetwork connection. Transfer Control Protocol and Internet Protocol(TCP/IP) are typical protocols for communicating between applicationservers 100 and the database system. However, it will be apparent to oneskilled in the art that other transport protocols may be used tooptimize the system depending on the network interconnect used.

In certain implementations, each application server 100 is configured tohandle requests for any user associated with any organization that is atenant. Because it is desirable to be able to add and remove applicationservers from the server pool at any time for any reason, there ispreferably no server affinity for a user and/or organization to aspecific application server 100. In one implementation, therefore, aninterface system implementing a load balancing function (e.g., an F5Big-IP load balancer) is communicably coupled between the applicationservers 100 and the user systems 12 to distribute requests to theapplication servers 100. In one implementation, the load balancer uses aleast connections algorithm to route user requests to the applicationservers 100. Other examples of load balancing algorithms, such as roundrobin and observed response time, also can be used. For example, incertain implementations, three consecutive requests from the same usercould hit three different application servers 100, and three requestsfrom different users could hit the same application server 100. In thismanner, by way of example, system 16 is multi-tenant, wherein system 16handles storage of, and access to, different objects, data andapplications across disparate users and organizations.

As an example of storage, one tenant might be a company that employs asales force where each salesperson uses system 16 to manage their salesprocess. Thus, a user might maintain contact data, leads data, customerfollow-up data, performance data, goals and progress data, etc., allapplicable to that user's personal sales process (e.g., in tenant datastorage 22). In an example of a MTS arrangement, since all of the dataand the applications to access, view, modify, report, transmit,calculate, etc., can be maintained and accessed by a user system havingnothing more than network access, the user can manage his or her salesefforts and cycles from any of many different user systems. For example,if a salesperson is visiting a customer and the customer has Internetaccess in their lobby, the salesperson can obtain critical updates as tothat customer while waiting for the customer to arrive in the lobby.

While each user's data might be separate from other users' dataregardless of the employers of each user, some data might beorganization-wide data shared or accessible by a plurality of users orall of the users for a given organization that is a tenant. Thus, theremight be some data structures managed by system 16 that are allocated atthe tenant level while other data structures might be managed at theuser level. Because an MTS might support multiple tenants includingpossible competitors, the MTS should have security protocols that keepdata, applications, and application use separate. Also, because manytenants may opt for access to an MTS rather than maintain their ownsystem, redundancy, up-time, and backup are additional functions thatmay be implemented in the MTS. In addition to user-specific data andtenant-specific data, system 16 might also maintain system level datausable by multiple tenants or other data. Such system level data mightinclude industry reports, news, postings, and the like that are sharableamong tenants.

In certain implementations, user systems 12 (which may be clientsystems) communicate with application servers 100 to request and updatesystem-level and tenant-level data from system 16 that may involvesending one or more queries to tenant data storage 22 and/or system datastorage 24. System 16 (e.g., an application server 100 in system 16)automatically generates one or more SQL statements (e.g., one or moreSQL queries) that are designed to access the desired information. Systemdata storage 24 may generate query plans to access the requested datafrom the database.

Each database can generally be viewed as a collection of objects, suchas a set of logical tables, containing data fitted into predefinedcategories. A “table” is one representation of a data object, and may beused herein to simplify the conceptual description of objects and customobjects according to some implementations. It should be understood that“table” and “object” may be used interchangeably herein. Each tablegenerally contains one or more data categories logically arranged ascolumns or fields in a viewable schema. Each row or record of a tablecontains an instance of data for each category defined by the fields.For example, a CRM database may include a table that describes acustomer with fields for basic contact information such as name,address, phone number, fax number, etc. Another table might describe apurchase order, including fields for information such as customer,product, sale price, date, etc. In some multi-tenant database systems,standard entity tables might be provided for use by all tenants. For CRMdatabase applications, such standard entities might include tables forcase, account, contact, lead, and opportunity data objects, eachcontaining pre-defined fields. It should be understood that the word“entity” may also be used interchangeably herein with “object” and“table”.

In some multi-tenant database systems, tenants may be allowed to createand store custom objects, or they may be allowed to customize standardentities or objects, for example by creating custom fields for standardobjects, including custom index fields. Commonly assigned U.S. Pat. No.7,779,039, titled CUSTOM ENTITIES AND FIELDS IN A MULTI-TENANT DATABASESYSTEM, by Weissman et al., issued on Aug. 17, 2010, and herebyincorporated by reference in its entirety and for all purposes, teachessystems and methods for creating custom objects as well as customizingstandard objects in a multi-tenant database system. In certainimplementations, for example, all custom entity data rows are stored ina single multi-tenant physical table, which may contain multiple logicaltables per organization. It is transparent to customers that theirmultiple “tables” are in fact stored in one large table or that theirdata may be stored in the same table as the data of other customers.

FIG. 2A shows a system diagram illustrating an example of architecturalcomponents of an on-demand database service environment 200 according tosome implementations. A client machine located in the cloud 204,generally referring to one or more networks in combination, as describedherein, may communicate with the on-demand database service environmentvia one or more edge routers 208 and 212. A client machine can be any ofthe examples of user systems 12 described above. The edge routers maycommunicate with one or more core switches 220 and 224 via firewall 216.The core switches may communicate with a load balancer 228, which maydistribute server load over different pods, such as the pods 240 and244. The pods 240 and 244, which may each include one or more serversand/or other computing resources, may perform data processing and otheroperations used to provide on-demand services. Communication with thepods may be conducted via pod switches 232 and 236. Components of theon-demand database service environment may communicate with a databasestorage 256 via a database firewall 248 and a database switch 252.

As shown in FIGS. 2A and 2B, accessing an on-demand database serviceenvironment may involve communications transmitted among a variety ofdifferent hardware and/or software components. Further, the on-demanddatabase service environment 200 is a simplified representation of anactual on-demand database service environment. For example, while onlyone or two devices of each type are shown in FIGS. 2A and 2B, someimplementations of an on-demand database service environment may includeanywhere from one to many devices of each type. Also, the on-demanddatabase service environment need not include each device shown in FIGS.2A and 2B, or may include additional devices not shown in FIGS. 2A and2B.

Moreover, one or more of the devices in the on-demand database serviceenvironment 200 may be implemented on the same physical device or ondifferent hardware. Some devices may be implemented using hardware or acombination of hardware and software. Thus, terms such as “dataprocessing apparatus,” “machine,” “server” and “device” as used hereinare not limited to a single hardware device, but rather include anyhardware and software configured to provide the described functionality.

The cloud 204 is intended to refer to a data network or plurality ofdata networks, often including the Internet. Client machines located inthe cloud 204 may communicate with the on-demand database serviceenvironment to access services provided by the on-demand databaseservice environment. For example, client machines may access theon-demand database service environment to retrieve, store, edit, and/orprocess information.

In some implementations, the edge routers 208 and 212 route packetsbetween the cloud 204 and other components of the on-demand databaseservice environment 200. The edge routers 208 and 212 may employ theBorder Gateway Protocol (BGP). The BGP is the core routing protocol ofthe Internet. The edge routers 208 and 212 may maintain a table of IPnetworks or ‘prefixes’, which designate network reachability amongautonomous systems on the Internet.

In one or more implementations, the firewall 216 may protect the innercomponents of the on-demand database service environment 200 fromInternet traffic. The firewall 216 may block, permit, or deny access tothe inner components of the on-demand database service environment 200based upon a set of rules and other criteria. The firewall 216 may actas one or more of a packet filter, an application gateway, a statefulfilter, a proxy server, or any other type of firewall.

In some implementations, the core switches 220 and 224 are high-capacityswitches that transfer packets within the on-demand database serviceenvironment 200. The core switches 220 and 224 may be configured asnetwork bridges that quickly route data between different componentswithin the on-demand database service environment. In someimplementations, the use of two or more core switches 220 and 224 mayprovide redundancy and/or reduced latency.

In some implementations, the pods 240 and 244 may perform the core dataprocessing and service functions provided by the on-demand databaseservice environment. Each pod may include various types of hardwareand/or software computing resources. An example of the pod architectureis discussed in greater detail with reference to FIG. 2B.

In some implementations, communication between the pods 240 and 244 maybe conducted via the pod switches 232 and 236. The pod switches 232 and236 may facilitate communication between the pods 240 and 244 and clientmachines located in the cloud 204, for example via core switches 220 and224. Also, the pod switches 232 and 236 may facilitate communicationbetween the pods 240 and 244 and the database storage 256.

In some implementations, the load balancer 228 may distribute workloadbetween the pods 240 and 244. Balancing the on-demand service requestsbetween the pods may assist in improving the use of resources,increasing throughput, reducing response times, and/or reducingoverhead. The load balancer 228 may include multilayer switches toanalyze and forward traffic.

In some implementations, access to the database storage 256 may beguarded by a database firewall 248. The database firewall 248 may act asa computer application firewall operating at the database applicationlayer of a protocol stack. The database firewall 248 may protect thedatabase storage 256 from application attacks such as structure querylanguage (SQL) injection, database rootkits, and unauthorizedinformation disclosure.

In some implementations, the database firewall 248 may include a hostusing one or more forms of reverse proxy services to proxy trafficbefore passing it to a gateway router. The database firewall 248 mayinspect the contents of database traffic and block certain content ordatabase requests. The database firewall 248 may work on the SQLapplication level atop the TCP/IP stack, managing applications'connection to the database or SQL management interfaces as well asintercepting and enforcing packets traveling to or from a databasenetwork or application interface.

In some implementations, communication with the database storage 256 maybe conducted via the database switch 252. The multi-tenant databasestorage 256 may include more than one hardware and/or softwarecomponents for handling database queries. Accordingly, the databaseswitch 252 may direct database queries transmitted by other componentsof the on-demand database service environment (e.g., the pods 240 and244) to the correct components within the database storage 256.

In some implementations, the database storage 256 is an on-demanddatabase system shared by many different organizations. The on-demanddatabase system may employ a multi-tenant approach, a virtualizedapproach, or any other type of database approach. An on-demand databasesystem is discussed in greater detail with reference to FIGS. 1A and 1B.

FIG. 2B shows a system diagram further illustrating an example ofarchitectural components of an on-demand database service environmentaccording to some implementations. The pod 244 may be used to renderservices to a user of the on-demand database service environment 200. Insome implementations, each pod may include a variety of servers and/orother systems. The pod 244 includes one or more content batch servers264, content search servers 268, query servers 282, file servers 286,access control system (ACS) servers 280, batch servers 284, and appservers 288. Also, the pod 244 includes database instances 290, quickfile systems (QFS) 292, and indexers 294. In one or moreimplementations, some or all communication between the servers in thepod 244 may be transmitted via the switch 236.

In some implementations, the app servers 288 may include a hardwareand/or software framework dedicated to the execution of procedures(e.g., programs, routines, scripts) for supporting the construction ofapplications provided by the on-demand database service environment 200via the pod 244. In some implementations, the hardware and/or softwareframework of an app server 288 is configured to execute operations ofthe services described herein, including performance of the blocks ofmethods described with reference to FIGS. 3-9C. In alternativeimplementations, two or more app servers 288 may be included andcooperate to perform such methods, or one or more other serversdescribed herein can be configured to perform the disclosed methods.

The content batch servers 264 may handle requests internal to the pod.These requests may be long-running and/or not tied to a particularcustomer. For example, the content batch servers 264 may handle requestsrelated to log mining, cleanup work, and maintenance tasks.

The content search servers 268 may provide query and indexer functions.For example, the functions provided by the content search servers 268may allow users to search through content stored in the on-demanddatabase service environment.

The file servers 286 may manage requests for information stored in theFile storage 298. The File storage 298 may store information such asdocuments, images, and basic large objects (BLOBs). By managing requestsfor information using the file servers 286, the image footprint on thedatabase may be reduced.

The query servers 282 may be used to retrieve information from one ormore file systems. For example, the query system 282 may receiverequests for information from the app servers 288 and then transmitinformation queries to the NFS 296 located outside the pod.

The pod 244 may share a database instance 290 configured as amulti-tenant environment in which different organizations share accessto the same database. Additionally, services rendered by the pod 244 maycall upon various hardware and/or software resources. In someimplementations, the ACS servers 280 may control access to data,hardware resources, or software resources.

In some implementations, the batch servers 284 may process batch jobs,which are used to run tasks at specified times. Thus, the batch servers284 may transmit instructions to other servers, such as the app servers288, to trigger the batch jobs.

In some implementations, the QFS 292 may be an open source file systemavailable from Sun Microsystems® of Santa Clara, Calif. The QFS mayserve as a rapid-access file system for storing and accessinginformation available within the pod 244. The QFS 292 may support somevolume management capabilities, allowing many disks to be groupedtogether into a file system. File system metadata can be kept on aseparate set of disks, which may be useful for streaming applicationswhere long disk seeks cannot be tolerated. Thus, the QFS system maycommunicate with one or more content search servers 268 and/or indexers294 to identify, retrieve, move, and/or update data stored in thenetwork file systems 296 and/or other storage systems.

In some implementations, one or more query servers 282 may communicatewith the NFS 296 to retrieve and/or update information stored outside ofthe pod 244. The NFS 296 may allow servers located in the pod 244 toaccess information to access files over a network in a manner similar tohow local storage is accessed.

In some implementations, queries from the query servers 222 may betransmitted to the NFS 296 via the load balancer 228, which maydistribute resource requests over various resources available in theon-demand database service environment. The NFS 296 may also communicatewith the QFS 292 to update the information stored on the NFS 296 and/orto provide information to the QFS 292 for use by servers located withinthe pod 244.

In some implementations, the pod may include one or more databaseinstances 290. The database instance 290 may transmit information to theQFS 292. When information is transmitted to the QFS, it may be availablefor use by servers within the pod 244 without using an additionaldatabase call.

In some implementations, database information may be transmitted to theindexer 294. Indexer 294 may provide an index of information availablein the database 290 and/or QFS 292. The index information may beprovided to file servers 286 and/or the QFS 292.

III. Updating a Web Application Displayed on a Client Machine

FIG. 3 shows a flowchart of an example of a computer implemented method300 for updating a web application displayed on a client machine,according to some implementations. The method 300 can be performed by orusing any suitable computing device, computing system or any number ofcomputing devices or systems that may cooperate to perform the method300. In some implementations, each of the blocks of the method 300 canbe performed wholly or partially by or using the database system 16 ofFIGS. 1A and 1B, or other suitable devices or components (includingprocessors) described herein, or the like.

In FIG. 3, at block 310, a server hosting the web application maintainsa database of application identifiers. In some implementations, a webapplication may be hosted on one or more application servers anddisplayed in a browser of a mobile or desktop device. The webapplication may include one or more components that are developed withina UI framework. In some implementations, the UI framework may provide aset of prebuilt components that may be assembled and configured to formnew components in a web application.

A component is a self-contained and potentially reusable section of UI.As a non-limiting example, a component may be a button, a text field, adate picker, a checkbox, or a dropdown list. A component may range ingranularity from a single line of text to an entire application. In someimplementations, a component may include other components within it, aswell as HTML, CSS, JavaScript, or any other Web-enabled code. In someimplementations, the browser of the client machine renders thecomponents of an application to produce HTML DOM (Document Object Model)elements to be displayed within the browser. A component definition fora component may describe metadata for the component, such as thecomponent's name, location of origin, or descriptor. A componentdescriptor may act as a key for a component definition stored in aregistry.

In some implementations, by utilizing self-contained and reusablecomponents, the UI framework may improve overall application developmentefficiency by facilitating parallel design. The UI framework may allow adeveloper building an application to extend a component, or to implementa component interface. A component may be encapsulated such that itsinternal implementation details remain private, while its public shapeand interface is visible to consumers of the component. The public shapeof a component may be defined by the attributes that can be set and theevents that interact with the component. In some implementations, an APImay expose these attributes and events to developers interacting withthe component. Separating the component's internal implementation fromits public shape may give component authors freedom to change theinternal implementation details of the component while insulatingcomponent consumers from those changes. As such, a component consumer isallowed to focus on building his web application using components basedon the components' published behavior and attributes, while thecomponent author continues to innovate and make changes to theunderlying implementation of the component.

Moreover, there may be different versions of a component, as thecomponent author changes the underlying implementation of the component.Because the component author may update the implementation of acomponent while the component is being used in an instance of a webapplication, a web application may be regarded as “out-of-date” if thereis a new version of one of the components of the web applicationavailable. A version of a component may be indicated with a componentversion identifier. As an example, a component version identifier for acomponent may be computed by performing an MD5 checksum of aconcatenated string representing the contents of the componentdefinition. A version of an instance of a web application displayed on aclient machine may be indicated by an application identifier, which maybe computed based on the component version identifiers of the componentsof the instance of the web application. As an example, the applicationidentifier may be computed by performing an MD5 checksum of theconcatenated component version identifiers of the application'sconstituent components. In this way, an application identifier for aninstance of a web application may be used to determine whether theinstance of the web application is up-to-date, that is, whether any ofthe web application's components have been updated.

Similarly, the application identifier may be used to determine whether acomponent has been reverted to a previous version. As an example, acomponent author may publish a new version of a component, and the newversion may be provided to one or more component consumers via webapplications containing the component. It may later be determined thatthe new version has a bug in it, and the component author may revert thecomponent to a previous version.

In some implementations, two different instances of a web applicationmay include different components, depending on the user interacting withthe web application. In other words, one instance of a web applicationmay include components that another instance of the web application maynot. For example, one organization in an on-demand service environmenthosting the web application may have access to more components andfeatures than another organization utilizing the same web application onthe same on-demand service environment. As another example, one user mayhave permissions that grant him access to particular components, andanother user may not have those permissions. In some implementations,the position of the user within the organization may also factor intowhich components the user may access via the web application. In anotherexample, the user may implement a personalization setting that causesparticular components to not be displayed in the user's instance of theweb application. In yet another example, a user may create a customcomponent that he wishes to add to the web application, such as a tabcontaining specific record information. The custom component may thenappear when that user accesses the web application.

In another implementation, where there are multiple versions of aparticular component, a user's personalization settings may designate aparticular version of the component that is not the most recent version.As such, while most users of the web application will be presented withthe latest version of the particular component, this user will bepresented with the version that he selected in his personalizationsettings.

When an instance of a web application is first initialized, anapplication identifier may be computed for the instance and stored in adatabase accessible to the server hosting the web application.Re-computing the application identifier at a later time and comparingthe re-computed application identifier with the stored applicationidentifier may notify the server as to whether any of the components ofthe instance of the web application have been updated.

The server may maintain a database of application identifiers that eachcorrespond to an instance of a web application displayed on a clientmachine and hosted by the server. As new instances of web applicationsare opened, a new application identifier for that instance may becalculated and stored in the database. When a client machine sends arequest to the server, the request may include an application identifierfor the version of the web application instance displayed on the clientmachine. This application identifier may be compared with the storedapplication identifiers to determine whether the version of the webapplication displayed on the client machine is current.

In some implementations, maintaining the database of applicationidentifiers may involve removing particular application identifiers fromthe database when a component is updated, as described herein.

First, the server may determine that a component has been updated. Theserver may become aware of this in various ways. For example, when acomponent has been updated by a component author and saved to acomponent database, the server may receive a notification of the update.The notification may be provided by a database trigger. Alternatively,the server may poll the file system containing the component definitionsto detect when a component has been updated by examining the lastmodified date of the component definition file. In anotherimplementation, a file system monitor may notify the server of changesto the component definition files in the file system.

When the server determines that a component has been updated, the servermay identify, in the database of application identifiers, anyapplication identifiers that are associated with web applicationscontaining the updated component. The definitions for the webapplications may be stored in the database and indexed by theapplication identifiers, such that the server can determine from anapplication identifier stored in the database whether the webapplication associated with the application contains the updatedcomponent. The server may then remove from the database the applicationidentifiers that correspond to web application containing the updatedcomponent.

Consequently, when a client machine displaying an outdated instance of aweb application communicates with the server and provides theapplication identifier for the outdated instance of the web application,the application identifier will not be found in the database ofapplication identifiers. An updated application identifier may becomputed using the updated component's new component version identifierand compared to the application identifier provided by the clientmachine.

In some implementations, when it is determined that a component has beenupdated, instead of selectively dumping the application identifiersassociated with applications containing the updated component, theserver may dump all of the application identifiers. In this situation,the absence of an application identifier in the database of applicationidentifiers does not necessarily mean that the instance of the webapplication displayed on the client machine is out-of-date. The absenceof the application identifier in the database triggers a re-computationof the application identifier for the web application. In the case thatnone of the components have been updated, the re-computed applicationidentifier will match the received application identifier, notifying theserver that the instance of the web application is up-to-date. In thecase that one or more of the components have been updated, there-computed application identifier will be different from thetransmitted application identifier, notifying the server that theinstance of the web application is out-of-date.

In FIG. 3, at block 320, the client machine sends to the server acommunication identifying a web application. The communication may be arequest from an instance of the web application running on the clientmachine. An example of such a communication may be an XHR(XMLHttpRequest) request configured to trigger an action on the server.The request may be handled by a server-side controller running on theserver. The first web application may be identified by the applicationname.

The communication also includes an application identifier correspondingto the instance of the web application running on the client machine. Insome implementations, the application identifier is first received fromthe server when the client machine first requests the web application.The request for the web application may cause the server to compute theapplication identifier based on the version identifiers of all of thecomponents of the requested web application. In some implementations,the client machine running the instance of the web application transmitsthe application identifier along with requests to the server to identifythe web application and to inform periodic determinations of whether theinstance of the web application is updated.

The web application that is identified by the communication receivedfrom the client machine may include a set of components, and each of thecomponents running in that instance of the web application may have acomponent version identifier indicating the version of each componentprovided in that instance of the web application.

In FIG. 3, at block 330, the server searches the database of applicationidentifiers and determines that the first application identifierreceived from the client machine in the received communication is notpresently included in the database of application identifiers. In someimplementations, this may indicate to the server that a component of theinstance of the web application running on the client machine may beout-of-date.

In FIG. 3, at block 335, in order to determine whether one of thecomponents is out-of-date, the server generates an updated applicationidentifier for the instance of the first web application based on thecomponent version identifiers of the one or more components. The serverhas access to the latest component versions for all of the components ofthe web application. As such, an updated application identifier may becomputed based on those component versions to calculate an updatedapplication identifier.

In some implementations, the application identifier may be computed byidentifying the entire set of components directly used in theapplication. In some cases, one component may be declared as adependency on another component if the one component is contained withinthe other component. As such, a dependency tree may be constructedcontaining all of the components of the web application and reflectingthe dependencies between the components. The application identifier maythen be computed by traversing the dependency tree and computing a hashof the component version identifiers of the components of the dependencytree.

In some situations, the updated application identifier matches theapplication identifier received from the client machine. This mayindicate that the instance of the web application running on the clientmachine is up-to-date. In other situations, the updated applicationidentifier is different from the application identifier received fromthe client machine, indicating that the instance of the web applicationrunning on the client machine includes at least one component that isout-of-date.

In FIG. 3, at block 340, the updated application identifier is stored inthe database of application identifiers. The database may also store theapplication descriptor, name, and/or definition along with theidentifier.

In FIG. 3, at block 350, a notification indicating that the instance ofthe first web application running on the first client machine isout-of-date is transmitted to the first client machine. The notificationmay also include the updated application identifier so that the clientmachine has a copy of the updated application identifier to submit alongwith subsequent communications with the server. In subsequent serverrequests from the client machine, as long as the updated applicationidentifier is included with the server request, the presence of theupdated application identifier in the database makes it unnecessary tore-compute the application identifier for the web application. Theserver, having received the updated application identifier anddetermined that the database contains the updated applicationidentifier, may proceed to respond to the request.

When the client machine receives the notification from the server, theclient machine may respond in various ways. In one implementation, theclient machine, via the web application, may notify the user of the webapplication that a component has been updated on the server and that theclient machine is providing an out-of-date version of the component. Theuser may be provided with an option to refresh the web application withan updated version of the component, or to continue displaying the webapplication with the out-of-date version of the component. In anotherimplementation, upon receiving the notification indicating that acomponent is out-of-date, the client machine may automatically send arequest to the server to refresh the web application.

In FIG. 3, at block 360, in an optional step, the server refreshes theweb application by performing the method 460 of FIG. 4.

FIG. 4 shows a flowchart of an example of a computer implemented method460 for refreshing a web application, according to some implementations.In FIG. 4, at block 462, the server receives, from the client machine, arequest for an updated instance of the first web application. The clientmachine, having received the notification transmitted by the serverindicating that the client machine's instance of the web application isout-of-date, may then transmit a request to the server for an updatedversion of the web application. The request that the client machinetransmits to the server may include the application name, or a uniquedescriptor for the application that allows the server to identify all ofthe components of the application.

The server may then, based on the descriptor for the application, lookfor all of the components that are required to build an instance of theapplication on the client machine. As described above, the required setof components may be identified by constructing a dependency treereflecting the dependencies between the components of the application.Given the set of components required to build the web application, theserver may then re-compute an application identifier for the instance ofthe web application based on the component versions of all of theconstituent components.

In FIG. 4, at block 464, the server responds to the client machine'srequest by transmitting a set of component identifiers to the clientmachine. The set of component identifiers allows the client machine touse the component identifiers to request each constituent component ofthe web application to be rendered in the refreshed instance of the webapplication. In some implementations, each component identifier may be aURL (uniform resource locator) or URI (uniform resource identifier) thatthe client machine may subsequently submit via an HTTP request to theserver to receive a component definition for the component identified bythe component identifier. As an example, the set of componentidentifiers may be a set of URL's that the server transmits to theclient.

In FIG. 4, at block 466, for each component to be rendered in therefreshed instance of the web application, the client machine transmitsa request to the server for a definition of the component. As mentionedabove, the request may be an HTTP request to the server using thecomponent identifier for the component. Once the server receives theHTTP request, the server may then build or retrieve the componentdefinition, instantiate the component definition, and send the componentdefinition and instance to the client machine.

In FIG. 4, at block 468, for each component to be rendered at the clientmachine, the server transmits the updated component definition to theclient machine to be rendered in the user interface of the refreshedinstance of the web application. The client that receives the componentdefinition uses the component definition to render the component in theuser interface.

FIG. 5 shows an example of a graphical user interface (GUI) 500 for aweb application containing one or more components, according to someimplementations. FIG. 5 includes a user interface 500 for an exampleapplication, “aura:note,” which allows a user to compose, display, sort,and search through one or more notes. The application includes a notelist component 510, which includes a search field component 512, asearch button component 514, a list component 516, a sort menu component518, and a create note component 519. The application also includes anote composition component 520, which includes a header component 522,an edit button component 524, a delete button component 526, and a textbox component 528.

These components of the “aura:note” application may be updated by thecomponent authors while a user is interacting with an instance of theapplication via a browser of, say, his mobile smartphone. For example,the list component 516 may have received an update from the componentauthor, but the client machine may be displaying the old version of thelist component. The server may determine that the instance of the webapplication running on the client is out-of-date when the instance ofthe web application sends a request to the server along with anapplication identifier. The server, having discarded from the databaseof application identifiers the application identifiers for instances ofthe web application that contain the updated component, will search thedatabase and find that the received application identifier does notexist in the database. As described above, the server may compute a newapplication identifier, determine that the new identifier is differentfrom the application identifier received from the client machine, andsend a notification to the client machine indicating that the instanceof the web application running on the client machine is out-of-date.

IV. Storing Client-Side Information for Identifying and RequestingServer-Side Actions

FIG. 6 shows a flowchart of an example of a computer implemented method600 for storing client-side information for identifying and requestingserver-side actions, according to some implementations. The method 600can be performed by or using any suitable computing device, computingsystem or any number of computing devices or systems that may cooperateto perform the method 600. In some implementations, each of the blocksof the method 600 can be performed wholly or partially by or using thedatabase system 16 of FIGS. 1A and 1B, or other suitable devices orcomponents (including processors) described herein, or the like.

In FIG. 6, at block 610, a mobile device displaying a user interface fora web application maintains a local cache storing client-sideinformation. As a user of the mobile device interacts with the webapplication, the web application responds to the user's interactions bytransmitting requests to the server hosting the web application. Whenthe web application receives the server's responses to the transmittedrequests, the web application may store the responses in a local cache,such that if the same requests are performed at a later time, the webapplication can use the cached responses to provide the responses,rather than sending another request to the server. By locally cachingparticular server responses, the web application can reduce bandwidthusage, server load, and perceived lag in interactions with theapplication.

In some implementations, the local cache may contain one or moreserver-side action responses indexed by an identifier for theserver-side action that generated each respective server-side actionresponse. The identifier for the server-side action may be a digitalfingerprint or hash function associated with the server-side action foruniquely identifying the server-side action in the local cache.

In some implementations, maintenance of the local cache—adding andremoving server-side action responses, and determining when to use thestored action responses—may be performed according to a local cachingpolicy. The local caching policy may be determined by a user of the webapplication, or an administrator of the server hosting the webapplication. The local caching policy may dictate a number of differentbehaviors with respect to the local cache.

For example, a user interacting with the web application on his mobiledevice may set up a set of policies for when the local cache should beused. In response to a request from a component of the web applicationto perform a server-side action, the default behavior may be to neveruse the local cache, in which case every request to perform aserver-side action will trigger a request to the server. A user mayprefer this policy if he is interacting with a web application thatdisplays information that is frequently changing. Alternatively, thedefault behavior may be to immediately return to the component the mostrecently cached response, followed by transmitting the request over tothe server to get an updated response to the server-side action. If theupdated response is different from the cached response, the cachedresponse may be replaced, and the updated response may then be providedto the component that requested the server-side action. This may beadvantageous so that the user does not experience any lag in hisinteractions with the web application, and so that the user eventuallygets the updated response from the server.

As another example, the user can set the local caching policy to includean expiration time for locally cached server responses. The user can setthe expiration time according to his understanding of how often hethinks the data he is interacting with will actually be refreshed. Forexample, if the user is a salesperson using the web application tomonitor constantly changing sales and opportunities data, he may set theexpiration time to a shorter period of time, so that the data displayedin the web application is frequently refreshed from the server. In someimplementations, the expiration time may be specified for a particularcomponent of the web application. This may be desirable for componentsthat display data that is frequently being updated, such as stockinformation. In some implementations, the other components may bedisplaying primarily static data, so it would be desirable to be able toset a short expiration time for a stock ticker component, and a longerexpiration time for the other components.

In another example, the local caching policy can specify that locallycached server responses should only be used when the mobile device isoffline and is unable to connect to the server.

In FIG. 6, at block 620, the mobile device, via a first component of theuser interface, may receive a request to perform a first server-sideaction on the server. The local cache, which includes the locally cachedserver-side responses, may include a response for the requestedserver-side action.

In FIG. 6, at block 630, the mobile device may also receive a requestfrom another component of the web application to perform a secondserver-side action on the server. The local cache may also include acached response for the requested second server-side action.

In FIG. 6, at block 640, the mobile device, given the two server-sideaction requests, determines, based on the local caching policy, that theweb application should communicate both requests to the server toperform the requested server-side actions. Alternatively, the localcaching policy may dictate that the mobile device just serve up thelocally cached responses without sending the server a request. In someimplementations, as discussed above, the local caching policy may causethe web application to provide the locally cached responses to thecomponents and to send the requested server-side action requests to theserver to retrieve updated responses.

In other implementations, the local caching policy may determine thatthe first cached server-side response be served to the requestingcomponent without sending the first server-side action request to theserver, and that the second server-side action request be transmitted tothe server. When the second server-side action request is transmitted tothe server, the local caching policy may determine that the secondcomponent wait for the server-side action response to be received fromthe server before providing response data to the second component.

In FIG. 6, at block 650, the mobile device causes the first and secondrequests to be communicated to the server. Because the local cachingpolicy may be implemented in an application programming interface (API)that provides a layer of abstraction above the individual serverrequests from each component of the web application, the API may manageall of the requests for the server from the client-side components ofthe web application by batching the individual requests, sending them tothe server together to be executed, returning the responses, cachingthem as appropriate, and serving them up to the requesting components.The API may also handle the policy decisions of when to serve up alocally cached response to a server-side action request from acomponent, or when to send a request to the server for an updatedresponse. In some implementations, the API may be a part of the userinterface framework that is used to build the web application, allowinga developer of a web application to just set his local caching policiesand allow the framework to handle the policy logic in responding toserver-side action requests from the various components of the webapplication.

In another implementation, the local caching policy may determine thatthe second request should not be transmitted to the server when thelocal cache already contains a cached response to the second request.Alternatively, the local caching policy may determine that the secondrequest should not be transmitted to the server when an identicalrequest was previously transmitted to the server and the client webapplication is still awaiting a response from the server.

FIG. 7 shows a flowchart of an example of a computer implemented method750 for a mobile device causing the first and second requests to becommunicated to the server, according to some implementations. Themethod 750 can be performed by or using any suitable computing device,computing system or any number of computing devices or systems that maycooperate to perform the method 750. In some implementations, each ofthe blocks of the method 750 can be performed wholly or partially by orusing the database system 16 of FIGS. 1A and 1B, or other suitabledevices or components (including processors) described herein, or thelike.

In some implementations, the mobile device running the web applicationmay provide the two cached responses to the requesting components. Inthis way, the components can be instantly updated based on locallycached information without requiring the user to wait on the server fora response. In some implementations, providing a component with thelocally cached information may not provide any new information to thecomponent, as the component may have previously been updated with thecached information.

In another implementation, however, a server-side action response mayhave been cached without providing the updated response to therequesting component. This may occur when the component submits arequest for a server-side action that takes the server longer thanexpected to complete. The component may have continued operating withoutwaiting for the response from the server. The response may subsequentlyarrive from the server and be directly stored in the local cache withoutproviding the response to the requesting component. The requestingcomponent may then request the same server-side action. In such a case,providing the requesting component with the cached response will givethe component an updated response.

In FIG. 7, at block 752, the mobile device transmits the first andsecond requests to the server as a single batch request. As discussedabove, the user interface framework used for building the webapplications may utilize an API to manage simultaneous connectionsbetween each component of a web application and the server. One way inwhich the web application may manage these simultaneous connections isby bundling multiple requests from different components into a singlebatch request and sending the batch request to the server. The bundledrequests may have been created around the same point in time, in whichcase bundling the requests into a single batch request may save onbandwidth and other resources required for transmitting the requestswithout sacrificing significant response time for the requests.

In FIG. 7, at block 754, the mobile device may receive from the server abatch response that includes updated server-side action responses forthe first and second requests that were transmitted to the server in thesingle batch request.

In some implementations, where a server-side action may take a longertime to execute, the batch response might include a server-side actionresponse for only one of the requests that was transmitted to the serverin the batch request. In this case, the longer server-side action mayreturn a response in a later batch response from the server to themobile device.

In some implementations, the batch response may also include delayedresponses to server-side action requests that were submitted to theserver in previous batch requests. This may occur where a previous batchrequest included a server-side action that took longer than expected toexecute on the server. The response may be sent back to the client webapplication with a subsequent batch response.

In FIG. 7, at block 756, the mobile device determines that the firstupdated server-side action response in the batch response is differentfrom the corresponding first server-side action response that waspreviously stored in the local cache. In other words, the response thatis currently stored in the local cache is out-of-date.

In FIG. 7, at block 758, the mobile device replaces the cached firstserver-side response with the first updated server-side action response,so that the local cache contains the updated response information.

In some implementations, the local caching policy may dictate that noresponses should be cached for the first server-side action. In someimplementations, when the mobile device stores a response in a localcache, the response may be stored in one of various types of localstorage using a storage service provided by the UI framework. Thestorage service may provide a caching infrastructure for clients runningweb applications using the UI framework, in which several types ofstorage are offered through adapters. Storage may be persistent and/orsecure. With persistent storage, cached data may be preserved betweenuser sessions in the browser running the web application. With securestorage, cached data may be encrypted. Different storage adapters maycorrespond to the different types of storage that may be utilized forthe local cache. For example, when the application requests persistentbut not secure storage, the application may be provided with a WebSQLadapter, which provides access to a client-side SQL database. If theapplication requests storage that is not persistent but secure, theapplication may be provided with access to the JavaScript main memoryspace for caching data. The stored cache may persist only per browserpage, such that browsing to a new page resets the cache.

When the storage is initialized, the web application developer maydesignate certain options, such as the name of the storage, whether thestorage is persistent and/or secure, the maximum cache size, theexpiration time, and the auto-refresh interval. The expiration time mayspecify the duration after which an item stored in the cache should bereplaced with a fresh copy. The auto-refresh interval may take effect ifan item has not expired yet. If the refresh interval for an item haspassed, the item may get refreshed after the same action is called.

What type of storage to use for caching purposes may be determined bythe local caching policy, which may be designated by the applicationdeveloper.

In FIG. 7, at block 760, the mobile device, upon receiving the batchresponse containing the first updated server-side action response,automatically provides the updated response to the first component. Theresponse may be provided to the component before or after the localcache is updated with the updated response. The first component, uponreceiving the updated response, may display the response data or processthe data as determined by the client-side controller running on themobile device.

In FIG. 7, at block 762, the mobile device may determine that the secondupdated server-side action response matches the locally cached secondserver-side action response. This may indicate that the response has notchanged, and the cached response is already updated.

In FIG. 7, at block 764, the web application may then notify the secondcomponent that the cached second response is up-to-date. The secondcomponent may respond by displaying an indication that the displayedinformation is up-to-date. Alternatively, the second component maysimply continue to run in the web application.

Returning to FIG. 6, at block 660, in an optional step, the mobiledevice may also receive, in the batch response from the server, apre-fetched action response corresponding to a predicted server-sideaction request. In some implementations, in addition to sending backresponses to previously submitted action requests, the server may also,based on previously submitted action requests, generate one or moreserver-side actions that are likely to be subsequently requested. Inthis way, the server can anticipate future server-side actions, executethe anticipated actions, and send the responses to the web applicationto be cached to be provided when the web application requests theanticipated actions. This may save on bandwidth usage for serverrequests, and may improve the response speed for the web application forresponses that have been pre-fetched and cached locally.

The server may utilize one or more prediction rules to predictserver-side actions that are likely to be subsequently requested by acomponent. For example, it may be that a sales agent that requestsinformation for an account is likely to subsequently request the mostrecent sales opportunities associated with the account. As such, theprediction rule may dictate that when an incoming batch request includesa request for account information, the batch response should include, inaddition to the account information, opportunity information for thethree most recent opportunities for that account. In someimplementations, the prediction rules may be based on a role orpersonalization settings of the user of the web application. As anotherexample, if a user searches for an account, and the search turns up alist of four accounts, it may be likely that the user will click on eachof those accounts to request more information. In this case, aprediction rule may determine that when a batch request includes asearch request that returns a list of accounts, account information forthose accounts should also be obtained from the server and provided inthe batch response so that the user can quickly access each of theaccounts of the search list. A prediction rule may consist of one ormore criteria actions and one or more pre-fetch actions, whereby, whenthe criteria actions are requested by the client web application, theone or more pre-fetch actions are also executed on the server, and thepre-fetch responses are provided in the batch response to be cached onthe client.

In FIG. 6, at block 670, in another optional step, the mobile devicestores the pre-fetched response in the local cache. When a component ofthe web application subsequently requests the same server-side actionresponse, the cached pre-fetched response may be provided to thecomponent without submitting a request to the server.

V. Displaying in a Web Browser a Web Application with an EmbeddedComponent

FIG. 8 shows a flowchart of an example of a computer implemented method800 for displaying in a web browser a presentation of a server-hostedweb application with an embedded component, according to someimplementations. The method 800 can be performed by or using anysuitable computing device, computing system or any number of computingdevices or systems that may cooperate to perform the method 800. In someimplementations, each of the blocks of the method 800 can be performedwholly or partially by or using the database system 16 of FIGS. 1A and1B, or other suitable devices or components (including processors)described herein, or the like.

In FIG. 8, at block 810, a mobile device running a web applicationexecutes a web browser, which generates a user interface for a webapplication. The web application is hosted by an application server incommunication with the computing device. In some implementations, theweb application may be an application developed and hosted by a user onone or more application servers.

In FIG. 8, at block 820, the mobile device displays the user interfaceof the web application. The display of the user interface includes anHTML container. The HTML container may contain HTML markup fordisplaying information for various components of the web application inthe user interface. The mobile device may use the HTML markup in theHTML container to render the user interface of the web application.

In FIG. 8, at block 830, the mobile device also provides an embeddedcomponent for display in the user interface. The embedded component maybe rendered based on code within the HTML container. The embeddedcomponent, perhaps unlike some of the other components of the userinterface, is hosted from a component server, different from theapplication server, in communication with the mobile device. Thecomponent server may include a set of self-contained and embeddablecomponents developed by other users to be imported into other webapplications and presented to users of the other web applications.

The resulting web application may include components hosted from theapplication server that hosts the web application, as well as embeddedcomponents hosted by the component server. All of the components may berendered based on HTML markup provided within the HTML container of theweb application. These components may communicate with one another usinga set of API's that create a transport layer that permits secure andauthenticated cross-domain communication between the embedded componenthosted on the component server and the components hosted on theapplication server. In some implementations, the authentication for thecross-domain communication may be performed by any authorizationframework that enables a third-party application to obtain limitedaccess to a web service, such as OAuth. The cross-domain communicationmay be accomplished using iframes, HTML5, or the like. An example of anAPI that facilitates this cross-domain capable transport layer isSalesforce Canvas™.

In some implementations, the components of the web application are ableto communicate with one another by raising events and listening toevents raised by other components. For example, a component may includeevent handlers to respond to events raised by another component. In someimplementations, the raised event may be triggered by user interaction,such as clicking on a component. In other implementations, the raisedevent may be triggered by activity not involving any user interaction.An event may include attributes that can be set before the event isfired and read when the event is handled by an event handler of acomponent. The component may publish a set of interface events that itunderstands and is configured to respond to. In some implementations, aclient-side controller may handle the events within a component. Theclient-side controller may be a JavaScript file that defines thefunctions for all of the component's actions performed in response todetected events.

In FIG. 8, at block 840, in an optional step, the mobile device respondsto an event raised by one of the components of the web application, asdescribed below in methods 930 and 940 of FIGS. 9A and 9B.

FIGS. 9A and 9B show flowcharts of examples of computer implementedmethods 930 and 940 for responding to an event raised by a component ofthe web application, according to some implementations.

In FIG. 9A, at block 932, the embedded component may be an informationfeed of an on-demand database system, and the other components of theweb application may be configured to raise events, which the embeddedcomponent recognizes and handles, identifying objects of the on-demanddatabase system. In some implementations, the information feed may be anenterprise social network feed. The enterprise social network feed ofthe embedded component may be configured to respond to the events bydisplaying information updates for the identified objects in theenterprise social network feed. At block 932, the mobile device receivesa selection, in one of the components of the web application, of anobject of the on-demand database system.

As an example, the web application may be a corporation internalwebsite, such as the Dell intranet, and the developer of the intranetmay wish to include in the internal site a Salesforce Chatter® feed, andhave the feed automatically follow any Salesforce-backed objects that anemployee encounters as he is navigating the Dell intranet. Instead ofdeveloping a separate feed component for the intranet, the SalesforceChatter® feed may already exist on the Salesforce servers as aself-contained, reusable component, built on the Salesforce UIframework, which the developer may embed in his web application. As theemployee browses the intranet, he may select an account record for aparticular Dell client to display in a component of the user interface.

In FIG. 9A, at block 934, the mobile device provides, to the embeddedcomponent, an event identifying the selected object. For example, whenthe Dell employee selects the account record to be displayed, an eventis triggered and handled by the embedded component containing theChatter® feed.

In FIG. 9A, at block 936, the mobile device displays in the feed one ormore information updates associated with the selected object. Once theembedded component detects the event triggered by the selection of theaccount record, the feed may respond by searching the on-demand databasesystem for updates pertaining to the selected account record. In thisway, the feed may be context-sensitive, providing additional usefulinformation for records that the employee may be examining as henavigates the Dell intranet.

Turning to FIG. 9B, the embedded component may be a detail displaycomponent for a contact record, and one of the other components may be alist of contacts. At block 942, the mobile device may receive aselection of one of the contacts in a list of contacts displayed in theother component.

FIG. 10 shows an example of a graphical user interface (GUI) 1000 for aninstance of a web application containing one or more components,according to some implementations. The GUI 1000 includes a contact listcomponent 1010 and a contact detail display component 1020. In thisexample, the contact list component 1010 is hosted on the server thatthis web application is hosted on. And the contact detail displaycomponent is hosted on a different component server and has beenembedded into this web application. The user of the web application hasselected “Arthur Song” 1012 from the contact list component 1010.

In FIG. 9B, at block 946, the mobile device raises an event identifyingthe selected contact. The embedded component includes an event handlerthat can handle this event. In the example of FIG. 10, when the userselects “Arthur Song” 1012 from the contact list component 1010, anevent is triggered, which the contact list component 1010 detects andhandles.

In FIG. 9B, at block 948, the mobile device displays, in the detaildisplay component, information for the selected contact. In FIG. 10,Arthur Song's contact details are then displayed in the detail displaycomponent in response to the event raised when the contact was selectedin the contact list.

The specific details of the specific aspects of implementationsdisclosed herein may be combined in any suitable manner withoutdeparting from the spirit and scope of the disclosed implementations.However, other implementations may be directed to specificimplementations relating to each individual aspect, or specificcombinations of these individual aspects.

While the disclosed examples are often described herein with referenceto an implementation in which an on-demand database service environmentis implemented in a system having an application server providing afront end for an on-demand database service capable of supportingmultiple tenants, the present implementations are not limited tomulti-tenant databases nor deployment on application servers.Implementations may be practiced using other database architectures,i.e., ORACLE®, DB2®, by IBM and the like without departing from thescope of the implementations claimed.

It should be understood that some of the disclosed implementations canbe embodied in the form of control logic using hardware and/or usingcomputer software in a modular or integrated manner. Other ways and/ormethods are possible using hardware and a combination of hardware andsoftware.

Any of the software components or functions described in thisapplication may be implemented as software code to be executed by aprocessor using any suitable computer language such as, for example,Java, C++ or Perl using, for example, conventional or object-orientedtechniques. The software code may be stored as a series of instructionsor commands on a computer-readable medium for storage and/ortransmission, suitable media include random access memory (RAM), a readonly memory (ROM), a magnetic medium such as a hard-drive or a floppydisk, or an optical medium such as a compact disk (CD) or DVD (digitalversatile disk), flash memory, and the like. The computer-readablemedium may be any combination of such storage or transmission devices.Computer-readable media encoded with the software/program code may bepackaged with a compatible device or provided separately from otherdevices (e.g., via Internet download). Any such computer-readable mediummay reside on or within a single computing device or an entire computersystem, and may be among other computer-readable media within a systemor network. A computer system, or other computing device, may include amonitor, printer, or other suitable display for providing any of theresults mentioned herein to a user.

While various implementations have been described herein, it should beunderstood that they have been presented by way of example only, and notlimitation. Thus, the breadth and scope of the present applicationshould not be limited by any of the implementations described herein,but should be defined only in accordance with the following andlater-submitted claims and their equivalents.

What is claimed is:
 1. A system comprising: a database systemimplemented using a server system comprising one or more processors, thedatabase system configurable to cause: maintaining, using the databasesystem, a database of application identifiers identifying a plurality ofweb applications including a first web application being displayable ata first client machine, the first web application comprising a pluralityof components, each component having a component version identifierindicating a version of the component, the first web application beingidentified by a first application identifier generated based on acalculation of each component version identifier of the components;identifying, using the database system, a first component versionidentifier of a first one of the components, the first component capableof being stored in a cache of the first client machine; processing anotification indicating that the first component has been updated, theupdated first component having an updated component version identifier;processing a request associated with the first web application from thefirst client machine; identifying, using the database system, a set ofcomponent version identifiers associated with each component of thefirst web application, the identified set of component versionidentifiers comprising the updated component version identifier;generating, using the database system, a second application identifierby traversing a dependency tree of the components to compute a hash ofthe identified set of component version identifiers of the components ofthe dependency tree; determining, using the database system, that thefirst application identifier is different from the second applicationidentifier; storing the second application identifier as one of theapplication identifiers in the database; and transmitting a notificationindicating that the first web application is out-of-date, thenotification comprising the second application identifier.
 2. The systemof claim 1, wherein the determination that the first applicationidentifier is different from the second application identifier indicatesthat an instance of the first web application on the first clientmachine comprises at least one out-of-date component.
 3. The system ofclaim 1, the database system further configurable to cause: transmittinga response to the first client machine, the response comprising anidentifier for the first component to be included in an updated instanceof the first web application.
 4. The system of claim 3, the databasesystem further configurable to cause: processing a component request fora definition of a component; and transmitting an updated componentdefinition to the first client machine to be rendered in a userinterface at the first client machine.
 5. The system of claim 1, whereinmaintaining the database of application identifiers comprises:determining that a component has been updated; identifying, using thedatabase system, one or more application identifiers associated with webapplications comprising the updated component; and removing theidentified application identifiers from the database.
 6. The system ofclaim 5, wherein determining that a component has been updated comprisesreceiving a notification from a component database that a component hasbeen updated, the notification comprising an updated component versionidentifier, and wherein the updated application identifier is generatedbased in part on the updated component version identifier for theupdated component.
 7. The system of claim 1, wherein the first componentis selected from a set of components associated with the first webapplication based on one or more criteria, the one or more criteriacomprising one or more of: a role of a user of the first webapplication, a position of the user, or a personalization setting of theuser.
 8. The system of claim 1, wherein the request is an XHR(XMLHttpRequest) request configured to trigger an action on the one ormore servers.
 9. The system of claim 1, wherein the second applicationidentifier is stored and indexed in the database according to anattribute of the first web application, the attribute being anapplication name or an application descriptor.
 10. A method comprising:maintaining, using a database system, a database of applicationidentifiers identifying a plurality of web applications including afirst web application being displayable at a first client machine, thefirst web application comprising a plurality of components, eachcomponent having a component version identifier indicating a version ofthe component, the first web application being identified by a firstapplication identifier generated based on a calculation of eachcomponent version identifier of the components; identifying, using thedatabase system, a first component version identifier of a first one ofthe components, the first component capable of being stored in a cacheof the first client machine; processing a notification indicating thatthe first component has been updated, the updated first component havingan updated component version identifier; processing a request associatedwith the first web application from the first client machine;identifying, using the database system, a set of component versionidentifiers associated with each component of the first web application,the identified set of component version identifiers comprising theupdated component version identifier; generating, using the databasesystem, a second application identifier by traversing a dependency treeof the components to compute a hash of the identified set of componentversion identifiers of the components of the dependency tree;determining, using the database system, that the first applicationidentifier is different from the second application identifier; storingthe second application identifier as one of the application identifiersin the database; and transmitting a notification indicating that thefirst web application is out-of-date, the notification comprising thesecond application identifier.
 11. The method of claim 10, wherein thedetermination that the first application identifier is different fromthe second application identifier indicates that an instance of thefirst web application on the first client machine comprises at least oneout-of-date component.
 12. The method of claim 10, the method furthercomprising: transmitting a response to the first client machine, theresponse comprising an identifier for the first component to be includedin an updated instance of the first web application.
 13. The method ofclaim 12, the method further comprises: processing a component requestfor a definition of a component; and transmitting an updated componentdefinition to the first client machine to be rendered in a userinterface at the first client machine.
 14. A computer program productcomprising computer-readable program code to be executed by one or moreprocessors when retrieved from a non-transitory computer-readablemedium, the program code including instructions configured to cause:maintaining, using a database system, a database of applicationidentifiers identifying a plurality of web applications including afirst web application being displayable at a first client machine, thefirst web application comprising a plurality of components, eachcomponent having a component version identifier indicating a version ofthe component, the first web application being identified by a firstapplication identifier generated based on a calculation of eachcomponent version identifier of the components; identifying, using thedatabase system, a first component version identifier of a first one ofthe components, the first component capable of being stored in a cacheof the first client machine; processing a notification indicating thatthe first component has been updated, the updated first component havingan updated component version identifier; processing a request associatedwith the first web application from the first client machine;identifying, using the database system, a set of component versionidentifiers associated with each component of the first web application,the identified set of component version identifiers comprising theupdated component version identifier; generating, using the databasesystem, a second application identifier by traversing a dependency treeof the components to compute a hash of the identified set of componentversion identifiers of the components of the dependency tree;determining, using the database system, that the first applicationidentifier is different from the second application identifier; storingthe second application identifier as one of the application identifiersin the database; and transmitting a notification indicating that thefirst web application is out-of-date, the notification comprising thesecond application identifier.
 15. The computer program product of claim14, wherein the determination that the first application identifier isdifferent from the second application identifier indicates that aninstance of the first web application on the first client machinecomprises at least one out-of-date component.
 16. The computer programproduct of claim 14, the instructions further configured to cause:transmitting a response to the first client machine, the responsecomprising an identifier for the first component to be included in anupdated instance of the first web application.
 17. The computer programproduct of claim 16, the instructions further configured to cause:processing a component request for a definition of a component; andtransmitting an updated component definition to the first client machineto be rendered in a user interface at the first client machine.